Cellusys

About Cellusys

At Cellusys, we empower mobile operators to grow revenue, secure their networks, and enhance subscriber experience. Our technology gives operators clear insights and comprehensive control over signalling, with a focus on roaming, security, IoT, and analytics. Our products are consistently rated #1 year after year across Signalling Firewall, Steering of Roaming, SMS Firewall, and Voice Firewall — a distinction no other vendor has achieved. Since our inception in 2005, when we brought together a team with a depth of expertise in signalling, technology, and IP not seen elsewhere, we have continually led the way — in deploying Diameter-ready Steering of Roaming and Signalling Firewall systems, advancing event-driven steering, and supporting multi-generation mobile networks from 2G to 5G. Today, our solutions serve more than 1.35 billion subscribers worldwide. Driven by innovation, customer collaboration, and a readiness to rethink how things should be done, we remain the commercial and common-sense choice for mobile network operators.